Car navigation system have revolutionized driving by providing accurate step-by-step instruction on how to go to a specified destination. But despite their enormous benefits, one problem with existing navigation system is that data entry is awkward. Each destination must generally be entered into the system one at a time, and the data entry process can be made difficult by awkward user interfaces. Even after all the destination data is entered, the user interfaces usually make any follow-on interaction with the navigation system awkward as well.